Multimorbidity and mortality among older patients with coronary heart disease in Shenzhen,China

BACKGROUND The current understanding of the magnitude and consequences of multimorbidity in Chinese older adults with coronary heart disease(CHD)is insufficient.We aimed to assess the association and population-attributable fractions(PAFs)between multimorbidity and mortality among hospitalized older patients who were diagnosed with CHD in Shenzhen,China.METHODS We conducted a retrospective cohort study of older Chinese patients(aged≥65 years)who were diagnosed with CHD.Cox proportional hazards models were used to estimate the associations between multimorbidity and all-cause and cardiovascular disease(CVD)mortality.We also calculated the PAFs.RESULTS The study comprised 76,455 older hospitalized patients who were diagnosed with CHD between January 1,2016,and August 31,2022.Among them,70,217(91.9%)had multimorbidity,defined as the presence of at least one of the predefined 14 chronic conditions.Those with cancer,hemorrhagic stroke and chronic liver disease had the worst overall death risk,with adjusted HRs(95%CIs)of 4.05(3.77,4.38),2.22(1.94,2.53),and 1.85(1.63,2.11),respectively.For CVD mortality,the highest risk was observed for hemorrhagic stroke,ischemic stroke,and chronic kidney disease;the corresponding adjusted HRs(95%CIs)were 3.24(2.77,3.79),1.91(1.79,2.04),and 1.81(1.64,1.99),respectively.All-cause mortality was mostly attributable to cancer,heart failure and ischemic stroke,with PAFs of 11.8,10.2,and 9.1,respectively.As for CVD mortality,the leading PAFs were heart failure,ischemic stroke and diabetes;the corresponding PAFs were 18.0,15.7,and 6.1,respectively.CONCLUSIONS Multimorbidity was common and had a significant impact on mortality among older patients with CHD in Shenzhen,China.Cancer,heart failure,ischemic stroke and diabetes are the primary contributors to PAFs.Therefore,prioritizing improved treatment and management of these comorbidities is essential for the survival prognosis of CHD patients from a holistic public health perspective.

Association of cardiometabolic multimorbidity with all-cause and cardiovascular disease mortality among Chinese hypertensive patients

BACKGROUND Hypertension usually clusters with multiple comorbidities.However,the association between cardiometabolic multimorbidity(CMM)and mortality in hypertensive patients is unclear.This study aimed to investigate the association between CMM and all-cause and cardiovascular disease(CVD)mortality in Chinese patients with hypertension.METHODS The data used in this study were from the China National Survey for Determinants of Detection and Treatment Status of Hypertensive Patients with Multiple Risk Factors(CONSIDER),which comprised 5006 participants aged 19–91 years.CMM was defined as the presence of one or more of the following morbidities:diabetes mellitus,dyslipidemia,chronic kidney disease,coronary heart disease,and stroke.Cox proportional hazard models were used to calculate the hazard ratios(HR)with 95%CI to determine the association between the number of CMMs and both all-cause and CVD mortality.RESULTS Among 5006 participants[mean age:58.6±10.4 years,50%women(2509 participants)],76.4%of participants had at least one comorbidity.The mortality rate was 4.57,4.76,8.48,and 16.04 deaths per 1000 person-years in hypertensive patients without any comorbidity and with one,two,and three or more morbidities,respectively.In the fully adjusted model,hypertensive participants with two cardiometabolic diseases(HR=1.52,95%CI:1.09–2.13)and those with three or more cardiometabolic diseases(HR=2.44,95%CI:1.71–3.48)had a significantly elevated risk of all-cause mortality.The findings were similar for CVD mortality but with a greater increase in risk magnitude.CONCLUSIONS In this study,three-fourths of hypertensive patients had CMM.Clustering with two or more comorbidities was associated with a significant increase in the risk of all-cause and cardiovascular mortality among hypertensive patients,suggesting more intensive treatment and control in this high-risk patient group.

Distributed Nash Equilibrium Seeking Strategies Under Quantized Communication

This paper is concerned with distributed Nash equi librium seeking strategies under quantized communication. In the proposed seeking strategy, a projection operator is synthesized with a gradient search method to achieve the optimization o players' objective functions while restricting their actions within required non-empty, convex and compact domains. In addition, a leader-following consensus protocol, in which quantized informa tion flows are utilized, is employed for information sharing among players. More specifically, logarithmic quantizers and uniform quantizers are investigated under both undirected and connected communication graphs and strongly connected digraphs, respec tively. Through Lyapunov stability analysis, it is shown that play ers' actions can be steered to a neighborhood of the Nash equilib rium with logarithmic and uniform quantizers, and the quanti fied convergence error depends on the parameter of the quan tizer for both undirected and directed cases. A numerical exam ple is given to verify the theoretical results.

Equilibrium Strategy of the Pursuit-Evasion Game in Three-Dimensional Space

The pursuit-evasion game models the strategic interaction among players, attracting attention in many realistic scenarios, such as missile guidance, unmanned aerial vehicles, and target defense. Existing studies mainly concentrate on the cooperative pursuit of multiple players in two-dimensional pursuit-evasion games. However, these approaches can hardly be applied to practical situations where players usually move in three-dimensional space with a three-degree-of-freedom control. In this paper,we make the first attempt to investigate the equilibrium strategy of the realistic pursuit-evasion game, in which the pursuer follows a three-degree-of-freedom control, and the evader moves freely. First, we describe the pursuer's three-degree-of-freedom control and the evader's relative coordinate. We then rigorously derive the equilibrium strategy by solving the retrogressive path equation according to the Hamilton-Jacobi-Bellman-Isaacs(HJBI) method, which divides the pursuit-evasion process into the navigation and acceleration phases. Besides, we analyze the maximum allowable speed for the pursuer to capture the evader successfully and provide the strategy with which the evader can escape when the pursuer's speed exceeds the threshold. We further conduct comparison tests with various unilateral deviations to verify that the proposed strategy forms a Nash equilibrium.

Magnetopause properties at the dusk magnetospheric flank from global magnetohydrodynamic simulations,the kinetic Vlasov equilibrium,and in situ observations--Potential implications for SMILE

We derived the properties of the terrestrial magnetopause(MP)from two modeling approaches,one global–fluid,the other local–kinetic,and compared the results with data collected in situ by the Magnetospheric Multiscale 2(MMS2)spacecraft.We used global magnetohydrodynamic(MHD)simulations of the Earth’s magnetosphere(publicly available from the NASA-CCMC[National Aeronautics and Space Administration–Community Coordinated Modeling Center])and local Vlasov equilibrium models(based on kinetic models for tangential discontinuities)to extract spatial profiles of the plasma and field variables at the Earth’s MP.The global MHD simulations used initial solar wind conditions extracted from the OMNI database at the time epoch when the MMS2 observes the MP.The kinetic Vlasov model used asymptotic boundary conditions derived from the same in situ MMS measurements upstream or downstream of the MP.The global MHD simulations provide a three-dimensional image of the magnetosphere at the time when the MMS2 crosses the MP.The Vlasov model provides a one-dimensional local view of the MP derived from first principles of kinetic theory.The MMS2 experimental data also serve as a reference for comparing and validating the numerical simulations and modeling.We found that the MP transition layer formed in global MHD simulations was generally localized closer to the Earth(roughly by one Earth radius)from the position of the real MP observed by the MMS.We also found that the global MHD simulations overestimated the thickness of the MP transition by one order of magnitude for three analyzed variables:magnetic field,density,and tangential speed.The MP thickness derived from the local Vlasov equilibrium was consistent with observations for all three of these variables.The overestimation of density in the Vlasov equilibrium was reduced compared with the global MHD solutions.We discuss our results in the context of future SMILE(Solar wind Magnetosphere Ionosphere Link Explorer)campaigns for observing the Earth’s MP.

Numerical analysis for the free-boundary current reversal equilibrium in the AC plasma current operation in a tokamak

In recent decades, tokamak discharges with zero total toroidal current have been reported in tokamak experiments, and this is one of the key problems in alternating current(AC) operations.An efficient free-boundary equilibrium code is developed to investigate such advanced tokamak discharges with current reversal equilibrium configuration. The calculation results show that the reversal current equilibrium can maintain finite pressure and also has considerable effects on the position of the X-point and the magnetic separatrix shape, and hence also on the position of the strike point on the divertor plates, which is extremely useful for magnetic design, MHD stability analysis, and experimental data analysis etc. for the AC plasma current operation on tokamaks.

Kinetic equilibrium reconstruction with internal safety factor profile constraints on EAST tokamak

Reconstruction of plasma equilibrium plays an important role in the analysis and simulation of plasma experiments. The kinetic equilibrium reconstruction with pressure and edge current constraints has been employed on EAST tokamak. However, the internal safety factor(q) profile is not accurate. This paper proposes a new way of incorporating q profile constraints into kinetic equilibrium reconstruction. The q profile is yielded from the Polarimeter Interferometer(POINT)reconstruction. Virtual probes containing information on q profile constraints are added to inputs of the kinetic equilibrium reconstruction program to obtain the final equilibrium. The new equilibrium produces a more accurate internal q profile. This improved method would help analyze EAST experiments.

Cardiometabolic and panvascular multimorbidity associated with motoric cognitive risk syndrome in older adults

Background Motoric cognitive risk(MCR)syndrome as a pre-dementia syndrome often co-occurring with chronic health condi-tions.This study aims to investigate the prevalence of MCR and its association with cardiometabolic and panvascular multimorb-idity among older people living in rural China.Methods This population-based study included 1450 participants who were aged≥60 years(66.2%women)and who underto-ok the second wave examination of the Confucius Hometown Aging Project in Shandong,China when information to define MCR was collected.Data were collected through in-person interviews,clinical examinations,and laboratory tests.Cardiometabolic and pa-nvascular multimorbidity were defined following the international criteria.MCR was defined as subjective cognitive complaints and slow gait speed in individuals free of dementia and functional disability.Multivariable logistic regression models were used to exa-mine the associations of MCR with multimorbidity.Results MCR was present in 6.3%of all participants,and the prevalence increased with advancing age.Cerebrovascular disea-se,ischemic heart disease,heart failure,and increased serum cystatin C were associated with increased likelihoods of MCR(mult-ivariable-adjusted odds ratio range:1.90-3.02,P<0.05 for all).Furthermore,there was a dose-response relationship between the nu-mber of cardiometabolic diseases and panvascular diseases and the likelihood of MCR.The multivariable-adjusted odds ratio(95%CI)of MCR associated with cardiometabolic and panvascular multimorbidity were 2.47(1.43-4.26)and 3.85(2.29-6.47),respectiv-ely.Conclusions Older adults with cardiometabolic and panvascular multimorbidity are at a higher likelihood of MCR.These fin-dings may have implications for identifying older adults at pre-dementia state as targets for early preventive interventions to delay dementia onset.

Psychiatric comorbidities in children with conduct disorder:a descriptive analysis of real-world data

To the editor:Two recent advisories from the US surgeon general have underscored the unprecedented public health crisis in youth mental health and emphasised the need for“timely data collection and research to identify and respond to youth mental health needs more rapidly”.1 Increased rates of suicidal behaviour,depression and anxiety symptoms and substance use.

Morbidity and Mortality of Newborns in a Context of Limited Resources in Tombouctou, Mali

Introduction: Worldwide, 2.3 million children died in the first 20 days after birth in 2022, according to the WHO. In Mali, according to the sixth Demographic and Health Survey, the neonatal mortality rate was estimated at 33% live births in 2018. The Timbuktu region had the highest neonatal mortality rate in the country with 44%. The objective of this work was to study the causes of neonatal morbidity and mortality and related factors in the paediatrics department of Timbuktu hospital. Materials and method: This was a descriptive, cross-sectional study conducted from 1 January to 31 December 2023 in the neonatology unit of the paediatrics department of Timbuktu hospital, including all newborns admitted to hospital. Results: Our study took place over 12 months, during which 618 admissions were made to the paediatric ward, including 244 newborns, i.e. 39.48%. The majority of newborns (86.5%) were admitted in the first week of life. The mean age was 3 days, with a sex ratio of 1.1 for males. Weight under 2500 g was 54.1% for an average weight of 2372 g. The main mode of admission was transfer from the hospital maternity unit (62%). The main reasons for admission were acute foetal distress (27.9%) and prematurity (26.2%). The average age of the mothers was 24, with extremes of 15 and 49. The mothers were housewives (87.3%), uneducated and primiparous (59% and 36.5% respectively);only 40.2% had made more than 3 antenatal care visits. Newborns born by vaginal delivery accounted for 80.7% and those born by caesarean section for 19.3%. The risk of infection was present in 52.5% of cases. The three leading causes of hospitalisation were birth asphyxia (40.2%), neonatal infection (32.4%) and prematurity (25%). The mortality rate was 21.7%. The main causes of death were prematurity (39.6%), birth asphyxia (32.1%) and neonatal infection (24.5%). Conclusion: Neonatal morbidity and mortality remain a concern in Timbuktu. Despite the unfavourable security situation, morbidity and mortality indicators are close to those in some hospitals in Mali. The correct application of Essential Newborn Care and antenatal care remains a major challenge for the hospital and the Timbuktu region.

Neonatal Morbidity and Mortality at Hospital Saint Camille de Ouagadougou (HOSCO): A Study from 2017 to 2020

Introduction: Neonatal pathology remains a real public health problem in developing countries. In Burkina Faso, this mortality has declined over the last ten years but remains below compared to the Sustainable Development Goals, which is 12 per 1000 living births at most by 2030. This study aims to identify specific causes of neonatal morbidity and mortality and will contribute to the implementation of preventive and curative measures aimed at reducing neonatal mortality at HOSCO. Method: This was a retrospective study using the records and database of newborns hospitalized from January 1srt, 2017 to December 31srt, 2020. Using logistic regression, the factors associated with mortality were determined. Results: During the study period, 3020 newborns were hospitalized. Most newborns (83.71%) were referred by a peripheral health facility. The average age at admission was 0.3 days ± 0.9 and the sex ratio was 1.2. Prematurity was the leading cause of hospitalization (61.13%) followed by neonatal infection (38.34%) and neonatal suffering (23.88%). The mortality rate was 40.6% with 82.71% cases of death in the early neonatal period. The main causes of death were low birth weight (47.39%), respiratory distress (18.76%), neonatal suffering (17.37%) and neonatal infection (13.87%). Home delivery, gestational age 36 weeks, number of PNC 4, concept of resuscitation, Apgar at the 5th minute 7, birth weight 2000 g and >4000 g, respiratory distress, hypothermia, neurological disorders were factors associated with deaths. Conclusion: Neonatal mortality is influenced by both maternal and fetal factors and many of them are preventable.

Post Episiotomy Morbidity among Parturient in Alex Ekwueme Federal University Teaching Hospital Abakaliki, Ebonyi State

Background: Episiotomy is a very common obstetric surgery, and it could be associated with serious complications. However, these complications largely are not noticed due to the shift of attention from mother to baby, after a successful delivery. Objective: To identify the morbidities associated with episiotomies and factors associated with such morbidities. Method: This was a questionnaire based cross sectional descriptive study among women who attended the Obstetric Department of Alex Ekwueme Federal University Teaching Hospital Abakaliki Ebonyi State, between 1st July and 31st Nov, 2023. The study population consisted of parturients who had episiotomies in their previous confinements, attending either the antenatal clinic or the postnatal clinic at Alex Ekwueme Federal University Teaching Hospital Abakaliki Ebonyi State. Results: Macrosomia was the most common indication of episiotomy at a rate of 31.6%. The majority of episiotomies were performed on the parturients in their first confinement at a rate of 64.5% and the majority of repairs were performed by the Registrar at a rate of 65.0%. Informed consent was obtained from 45.79% of parturients while 54.21% were not informed before the episiotomy was administered. Only 55.3% of the parturient received analgesia before episiotomy was administered. The majority of the parturients had their episiotomy repaired between 10 - 15 minutes at a rate of 40.3%. Postoperative pain at the rate of 44.5% was the most common complication and dyspareunia as a form of sexual complication was the commonest at a rate of 31.3%. Conclusion: The parturient needs to be properly counselled before administration of episiotomy and adequate analgesia should be given, as episiotomy is a surgical procedure. Proper training of health workers on both the technique of administering and repairing episiotomy is important. Restrictive use of routine episiotomy in primigravidae is advised to reduce the rate of episiotomy.

Morbidity and Mortality Related to Infectious Diseases in the Roi Boudouin Paediatric Ward in Senegal

Introduction: Infant and child morbidity and mortality linked to infections remain a major concern in both developed and developing countries. The general objective was to determine the characteristics of hospital morbidity and mortality linked to infectious pathologies in the pediatric department of the King Baudouin hospital center in Dakar. Methods: This was a retrospective, descriptive and analytical study focusing on children hospitalized from January 1, 2018 to December 31, 2021 in the pediatric department of the King Baudouin hospital center in Dakar. Results: During the study period, 1474 children were hospitalized for an infectious pathology in the pediatric department. The sex ratio was 1.48. Children aged between one and twelve months represented 34.12%. Morbidity due to respiratory and digestive infections was 42.33% and 33.45%, respectively. Pediatric hospital mortality was 0.75% with a predominance noted in infants between 1 and 12 months (55.86%). Respiratory, digestive infections, sepsis and neurological infections were the main causes of death. Factors associated with mortality were age (1 to 12 months) with p Conclusion: Reducing infant and child mortality linked to infectious diseases remains a crucial challenge to address for improving children’s health. Early detection of related signs, prevention of infections, and adequate care and monitoring of infants and children can contribute to this reduction.

Morbidity and Mortality during Anaesthesia in Patients with versus without Diabetes: Single-Centre Cohort Study

Background and objective: Classically, diabetic subjects are at high risk of anaesthesia compared with general population. However, some recent publications have shown contrasting and sometimes contrary results. The aim of our study was to evaluate morbidity and mortality during and after anaesthesia in patients with versus without diabetes operated on at Monkole Hospital over the last ten years. Methods: Retrospective cohort study including all patients who underwent all-comers surgery excluding cardiac surgery between 2011 and 2021. Each diabetic patient was matched to 2 non-diabetic controls on age and sex. The evaluation criterion was the frequency of occurrence of at least one perioperative complication and/or death up to day 30. A multivariate analysis using a Cox model was used to determine the factors associated with the occurrence of this morbidity and mortality. The model was adjusted for comorbidities, preoperative hyperglycaemia, ASA score, type of anaesthesia and severity of surgery. Results: A total of 351 diabetic patients (mean age 53.3 ± 14.18 years) and 701 non-diabetic patients (mean age 53.52 ± 14.7 years) were included and analysed. Preoperatively, hyperglycaemia (blood glucose > 180 mg/dl) was observed in 24.3% of diabetic patients compared with 1.6% of non-diabetic patients. The incidence of overall perioperative complications was 25.6% in diabetic patients compared with 28.6% in non-diabetic patients (p = 0.27). The risk factors associated with this morbidity were general anaesthesia with oro-tracheal intubation vs loco-regional anaesthesia (OR = 3.06 [95%CI: 1.91 - 4.94];p Conclusion: This study shows that there is not significant increase in perioperative morbidity and mortality in diabetic patients compared with non-diabetic ones of similar severity. These results suggest that diabetes itself (excluding associated comorbidities) has only a minor impact on perioperative morbidity and mortality.

Perinatal Morbidity and Mortality Associated with Maternal Diabetes in the Neonatology Department of the Issaka Gazoby Maternity Hospital, Niamey, Niger

Introduction: The association of diabetes and pregnancy is associated with a significantly higher risk of perinatal morbidity and mortality. The aim of this study was to investigate the perinatal morbidity and mortality associated with maternal diabetes at the Issaka Gazoby Maternity Hospital in Niamey. Methodology: This was a prospective case-control study conducted from April to September 2021 at the Issaka Gazoby Maternity Hospital in Niamey. “Cases” were neonates born to diabetic mothers, and “controls” were neonates born to non-diabetic mothers. The main dependent variable was the occurrence of perinatal complications. Analysis was performed using Epi info software 7.2.1. Pearson’s Chi2 test or Fisher’s exact test were used (p Results: Of the 2,225 admissions during the study period, 31 newborns were born to diabetic mothers (1.4%). Diabetic mothers were 2.8 times more likely to have a history of abortion (67.7% vs. 28.6%;OR = 2.82;p = 0.001). Similarly, a history of macrosomia was found in 29.0% of diabetic mothers versus 9.5% of controls (OR = 2.15;p = 0.01). Macrosomia was also more common in newborns of diabetic mothers (38.7% vs. 9.5%;OR = 2.63;p Conclusion: The risks of ante- and perinatal complications such as abortion, fetal macrosomia and stillbirth, as well as neonatal pathological events (macrosomia and malformations) were greater in newborns of diabetic mothers.

Morbidity and Mortality in the Emergency Department of the Albert Royer National Children’s Hospital Center Dakar: Prospective Study from January 1 to April 30, 2020

Introduction: Infant and child morbidity and mortality constitute a public health problem in Africa, particularly in Senegal. The objective of this work was to help identify the determinants this morbidity and mortality. Materials and Methods: A prospective study, over a 4-month period (January to April 2020). All patients aged 0 to 15 years, hospitalized for emergency reasons in the Albert Royer emergency department, were included. Mortality was analyzed according to sociodemographic data, the patient’s itinerary, transfer procedures, availability of emergency medications, diagnosis made during hospitalization and causes of death. The data were collected based on a protocol in an established file and analyzed by SPSS (Statistical Package for Science Social) software. Version 18. Results: 225 children in emergency situations were included. The age of our patients is between 0 and 15 years (minimum 0.23 months, maximum 191 months, average 47 months and standard deviation 54). Thus, emergencies represented 57.98% of the 388 hospitalizations. Seventy percent of patients were less than 60 months old with a male predominance (sex ratio 1.16), 2.22% were newborns and 27.11% were aged between 60 and 191 months). A total of 79 (35.1%) were transferred and only 57.4% received care before transfer. A total of 12 deaths were reported, representing a lethality of 5.3%. Only young age (less than 59 months, a mortality rate of 91.7%), cardiac decompensations, severe sepsis, and neonatal conditions were more associated with mortality. The majority of our deceased patients came from families with a low socio-economic level (83.3%). Conclusion: Pediatric emergencies are frequent and responsible for lethality and require the necessary efforts, particularly through parent education, the creation of emergency outpatient care units and, above all, the strengthening of the technical platform and therapeutic means.

Knee Arthroplasty Incidence Rate vs. Revision of Knee Arthroplasty and Its Associated Comorbidities in Colombia

Introduction: Total knee arthroplasty (TKA) has been established as a transformative solution in the treatment of advanced degenerative diseases of the knee, such as osteoarthritis, rheumatoid arthritis, and posttraumatic arthritis. In this sense, TKA surgery, which seeks to replace the damaged joint with prosthetic components, has proven to be highly effective in relieving pain, improving joint function, and, ultimately, significantly increasing patients’ quality of life. The present study describes the TKA and revision knee arthroplasty (RKA) rates and, identifies the associated co morbidities in the Colombian context. Methods: A retrospective cohort study was carried out. It describes demographic and clinical characteristics between two groups of patients, TKA or RKA, and its association with mortality at 30 days, 90 days, or one year after the intervention. Results: The incidence rate of the population undergoing TKA was approximately 11.71 cases per 100,000 inhabitants. Furthermore, the incidence rate for revision knee arthroplasty (RKA) procedures in the same period was around 0.96 per 100,000 inhabitants. In both groups at 30 days postoperatively, a total mortality rate of 0.09%was recorded. When the follow-up was extended to 90 days, it increased to 0.15%;at one year postoperatively, it rose to 0.88%. Conclusion: Mortality after surgery was low in Colombia in 2019. Although RKA is a beneficial procedure, in certain circumstances, it was noted that it carries a higher risk compared to primary TKA. Our results emphasize the importance of careful evaluation of co morbidities and risk factors in patients undergoing these surgical procedures. The application of quality-of-life questionnaires should be considered in future studies on effectiveness and mortality for TKA and RKA in our country.

Impact of Delivery Mode on Morbidity in Preterm Infants with Very Low Birth Weights (<1500 Grams)

The mode of delivery and gestational age for very-low-birth-weight (VLBW) preterm infants are not yet well established and are constant topics of debate. Objective: To analyze the impact of delivery mode on morbidity in preterm infants weighing less than 1500 g. Results: Among 21,957 births, 81 were analyzed;53 were delivered vaginally, and 28 were delivered by cesarean section. The median maternal age, gestational age and body mass index among those delivered vaginally and by cesarean section were 20 years and 22.5 years, 27.6 weeks and 30.1 weeks, and 26.0 kg/m2 and 27.8 kg/m2, respectively. With respect to neonatal blood gas parameters, for those born vaginally and by cesarean section, the median pH was 7.32 and 7.24, the pCO2 was 41.5 mmHg and 51.1 mmHg, and the pO2 was 22.3 mmHg and 16 mmHg. The median fetal weight among those born by cesarean section and vaginally were 1180 g and 955 g, respectively. The median Apgar scores at the first and fifth minutes among those born by cesarean section and vaginally were 5.00 and 8.00 and 4.50 and 7.00, respectively. Conclusion: There was no significant difference between the results of vaginal and cesarean delivery for VLBW infants. Thus, further studies on this subject are needed.

Effects of ionic liquids on the vapor-liquid equilibrium of 1,3,5-trioxane-water system at 101.3 kPa

Increasing the 1,3,5-trioxane(TOX) concentration in the equilibrated vapor phase of TOX-H_(2)O system has been recognized as a challenge for the azeotrope. Ionic liquids(ILs) were used to improve the relative volatility of TOX to H_(2)O and destroy the azeotrope in the TOX-H2O system. The vapor-liquid equilibrium of TOX-H2O system at 101.3 kPa was studied with the addition of 1-butyl-3-methylimidazolium hydrogen sulfate, 1-hexyl-3-methylimidazolium hydrogen sulfate and 1-butyl-3-methylimidazolium nitrate, respectively. The results showed that the volatility of TOX increased with the increase in IL dosage. And the volatility of water decreased with the increase in IL dosage. The relative volatility of TOX to H_(2)O was improved with the increase in ILs dosage. The azeotrope could be destroyed with an IL mole fraction of about 0.10. A non-random two-liquid(NRTL) model was successfully used to correlate the experimental data. The interaction parameters were obtained by fitting the experimental data with the model. The results indicated that a strong interaction existed between ILs and water. The strong interaction improved the volatility of TOX and inhibited the volatility of water, and then intensified the relative volatility of TOX to H_(2)O. The results showed that an ILs with strong polarity and hydrophilicity may be a potential additive to improve the TOX concentration in the equilibrated vapor phase.

Phase equilibrium data prediction and process optimizationin butadiene extraction process

In response to the lack of reliable physical parameters in the process simulation of the butadiene extraction,a large amount of phase equilibrium data were collected in the context of the actual process of butadiene production by acetonitrile.The accuracy of five prediction methods,UNIFAC(UNIQUAC Functional-group Activity Coefficients),UNIFAC-LL,UNIFAC-LBY,UNIFAC-DMD and COSMO-RS,applied to the butadiene extraction process was verified using partial phase equilibrium data.The results showed that the UNIFAC-DMD method had the highest accuracy in predicting phase equilibrium data for the missing system.COSMO-RS-predicted multiple systems showed good accuracy,and a large number of missing phase equilibrium data were estimated using the UNIFAC-DMD method and COSMO-RS method.The predicted phase equilibrium data were checked for consistency.The NRTL-RK(non-Random Two Liquid-Redlich-Kwong Equation of State)and UNIQUAC thermodynamic models were used to correlate the phase equilibrium data.Industrial device simulations were used to verify the accuracy of the thermodynamic model applied to the butadiene extraction process.The simulation results showed that the average deviations of the simulated results using the correlated thermodynamic model from the actual values were less than 2%compared to that using the commercial simulation software,Aspen Plus and its database.The average deviation was much smaller than that of the simulations using the Aspen Plus database(>10%),indicating that the obtained phase equilibrium data are highly accurate and reliable.The best phase equilibrium data and thermodynamic model parameters for butadiene extraction are provided.This improves the accuracy and reliability of the design,optimization and control of the process,and provides a basis and guarantee for developing a more environmentally friendly and economical butadiene extraction process.